Latch apparatus

ABSTRACT

Disclosed herein is a latch apparatus. The latch apparatus includes: a base formed with an opening; a latch gear formed with a mounting groove to lock a striker entering the mounting groove through the opening; a pawl rotatably disposed on the base and engaging with the latch gear to prevent rotation of the latch gear; a release lever disposed to adjoin the pawl, transmitting constraint force of pressing the pawl, and rotating the pawl to release the latch gear; a support shaft secured to the base, supporting a lateral surface of the pawl and transmitting the constraint force of pressing the pawl; and a guide portion rotatably provided to the support shaft, pressed to rotate by the release lever, and guiding movement of a projection pin provided to the pawl.

BACKGROUND

1. Technical Field

The present invention relates to a latch apparatus, and moreparticularly, to a latch apparatus which allows a latch gear to beeasily opened even by small force.

2. Description of the Related Art

Generally, in a latch apparatus for vehicles, a latch gear having amounting groove and a pawl for restricting a locking end of the latchgear are rotatably disposed on a base plate having an opening.

The pawl receives rotational force from a handle and releases the latchgear from restriction, thereby allowing a door to be opened.

The latch gear includes a first locking portion and a second lockingportion, thereby forming a two-stage locking condition in which thelatch gear locking a striker is locked by the pawl.

When the striker enters the mounting groove of the latch gear, the latchgear rotates in one direction and the pawl is locked to the firstlocking portion of the latch gear, thereby forming a first lockingstage.

When the latch gear is pushed by the striker and thus completelyrotated, the pawl is locked to the second locking portion of the latchgear, thereby forming a second locking stage.

To move the latch gear from a locking location of the second lockedstate to a release location, releasing force is transmitted to the pawlsuch that the pawl can be separated from the latch gear.

If the pawl receiving manipulation force from the handle is separatedfrom the latch gear, the latch gear is rotated in a releasing directionwhen opening force is applied to the door, thereby separating thestriker from the latch gear.

A door seal is disposed along an edge of the door of the vehicle toblock water and dust from entering the door.

The door seal is made of rubber and has elasticity. Thus, when the dooris closed, the door seal applies force to the door in an openingdirection.

In addition, the striker applies torque to the latch gear in a directionof releasing from the latch apparatus. The torque applied to the latchgear generates resistance to engagement between the latch gear and thepawl, thereby increasing a constraint force of the latch apparatuslocking the striker increases.

A background technique of the present invention is disclosed in KoreanPatent Publication No. 1998-0018831 (published on Jun. 5, 1998 andentitled “LATCH APPARATUS FOR VEHICLE REAR DOOR”).

When the door seal is compressed as the vehicle door is closed, the dooris urged in an opening direction by restoring force of the door seal,thereby increasing torque transmitted to the latch gear. To release thepawl from the latch having the increased torque, a force for operatingthe pawl must also be increased, thereby making it difficult for oldpersons or the like to operate the handle and open the door. There,there is a need for a latch apparatus overcoming such a problem.

BRIEF SUMMARY

The present invention has been conceived to solve the foregoing problemin the art, and an aspect of the present invention is to provide a latchapparatus which allows a latch gear to be easily opened even by smallforce.

In accordance with one aspect of the invention, a latch apparatusincludes: a base formed with an opening; a latch gear formed with amounting groove to lock a striker entering the mounting groove throughthe opening; a pawl rotatably disposed on the base and engaging with thelatch gear to prevent rotation of the latch gear; a release leverdisposed to adjoin the pawl, transmitting constraint force of pressingthe pawl, and rotating the pawl to release the latch gear; a supportshaft secured to the base, supporting a lateral surface of the pawl andtransmitting the constraint force of pressing the pawl; and a guideportion rotatably provided to the support shaft, pressed to rotate bythe release lever, and guiding movement of a projection pin provided tothe pawl.

The latch gear may include: a latch body formed with the mounting grooveand rotatably disposed on the base; a first locking portion protrudingfrom a lateral surface of the latch body and adjoining the pawl at afirst locking location; and a second locking portion separated from thefirst locking portion, protruding from the lateral surface of the latchbody, and adjoining the pawl at a second locking location.

The pawl may include: a pawl body provided with the projection pin andhaving a lateral surface adjoining the release lever and the supportshaft; a locking protrusion extending from one side of the pawl body andlocked to a lateral surface of the latch gear as the pawl body rotates;and an extended protrusion extending from the other side of the pawlbody and selectively adjoining a support lever secured to the base.

The release lever may include: a rotary portion rotatably disposed onthe base and pressing the pawl at different portions thereof changedwhen rotated; a lever body coupled to the rotary portion to rotatetogether with the rotary portion and transmitting operating forcemanually or automatically; and a lever protrusion protruding from thelever body and pressing the guide portion.

The rotary portion may include: a rotary body into which the lever bodyis inserted and locked and which externally forms a first curvedsurface; and a rotary protrusion protruding from an outer surface of therotary body, adjoining the lateral surface of the pawl, and externallyforming a second curved surface.

The guide portion may include: a guide body through which the supportshaft passes; a guide projection extending from the guide body andforming an inner space in which the projection pin moves; and a guideplate protruding from the guide body and elastically adjoining thelateral surface of the release lever.

The inner space may include an elongated hole.

The latch apparatus may further include a first elastic member supportedat opposite sides thereof by the pawl and the release lever, andpressing the pawl and the release lever to rotate in differentdirections.

The latch apparatus may further include: a movable connecting memberconnected to the release lever and moving together with the releaselever; and a coupling forming an operation space in which the movableconnecting member is locked and moved, and moved by operating forcereceived from a handle element.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of the inventionwill become apparent from the detailed description of exemplaryembodiments given in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic perspective view of a latch apparatus according toone embodiment of the present invention;

FIG. 2 is a schematic perspective view of a main configuration of thelatch apparatus according to the embodiment of the present invention;

FIG. 3 is a schematic perspective view of the latch apparatus accordingto the embodiment of the present invention, in which a first elasticmember is disposed on a first support shaft;

FIG. 4 is a schematic perspective view of the latch apparatus accordingto the embodiment of the present invention, in which a housing isseparated from a base;

FIG. 5 is an exploded perspective view of the latch apparatus accordingto the embodiment of the present invention;

FIG. 6 is a schematic plan view of the latch apparatus according to theembodiment of the present invention;

FIG. 7 is a view illustrating forces applied to a latch gear at a secondlocking location in which the latch gear is completely locked, in thelatch apparatus according to the embodiment of the present invention;

FIG. 8 is a force diagram showing a constraint force, a first reactionforce and a second reaction force shown in FIG. 7;

FIGS. 9a to 9f are views showing a locking sequence of the latchapparatus according to the embodiment of the present invention;

FIGS. 10a to 10e are views showing an opening sequence of the latchapparatus according to the embodiment of the present invention;

FIGS. 11a to 11f are views showing a locking sequence of a latchapparatus according to another embodiment of the present invention; and

FIGS. 12a to 12e are views showing an opening sequence of a latchapparatus according to another embodiment of the present invention.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings. Itshould be noted that the drawings are not to precise scale and may beexaggerated in thickness of lines or size of components for descriptiveconvenience and clarity. In addition, the terms used herein are definedby taking functions of the present invention into account and can bechanged according to user or operator custom or intention. Therefore,the terms should be defined according to the overall disclosure setforth herein.

FIG. 1 is a schematic perspective view of a latch apparatus according toone embodiment of the present invention; FIG. 2 is a schematicperspective view of a main configuration of the latch apparatusaccording to the embodiment of the present invention; FIG. 3 is aschematic perspective view of the latch apparatus according to theembodiment of the present invention, in which a first elastic member isdisposed on a first support shaft; FIG. 4 is a schematic perspectiveview of the latch apparatus according to the embodiment of the presentinvention, in which a housing is separated from a base; FIG. 5 is anexploded perspective view of the latch apparatus according to theembodiment of the present invention; FIG. 6 is a schematic plan view ofthe latch apparatus according to the embodiment of the presentinvention; FIG. 7 is a view illustrating a force applied to a latch gearat a second locking location in which the latch gear is completelylocked, in the latch apparatus according to the embodiment of thepresent invention; FIG. 8 is a force diagram showing a constraint force,a first reaction force and a second reaction force shown in FIG. 7;FIGS. 9a to 9f are views showing a locking sequence of the latchapparatus according to the embodiment of the present invention; andFIGS. 10a to 10e are views showing an opening sequence of the latchapparatus according to the embodiment of the present invention.

Referring to FIGS. 1 to 7, a latch apparatus 1 according to oneexemplary embodiment of the invention includes a base 20 formed with anopening 22; a latch gear 50 formed with a mounting groove 53 to lock astriker 10 entering the mounting groove through the opening 22; a pawl60 rotatably disposed on the base 20 and engaging with the latch gear 50to prevent rotation of the latch gear 50; a release lever 70 disposed toadjoin the pawl 60, transmitting constraint force F1 to press the pawl60, and rotating the pawl 60 to release the latch gear 50; a supportshaft 90 secured to the base 20, supporting a lateral surface of thepawl 60 and transmitting the constraint force F1 to press the pawl 60;and a guide portion 100 rotatably provided to the support shaft 90,pressed to rotate by the release lever 70, and guiding movement of aprojection pin 64 provided to the pawl 60.

In one embodiment, the base 20 and the cover plate 40 are formed of flatmetal plates, and the cover plate 40 and the base 20 are connected toeach other by a spindle-shaped rivet.

Other components of the latch apparatus 1 are disposed between the base20 and the cover plate 40 so as to lock or release the striker 10.

In one embodiment, the base 20 is fastened to a vehicle door, andincludes the opening 22 having a ‘U’-shape at one side thereof at whichthe striker 10 moves.

The striker 10 mounted on a chassis of a vehicle enters the opening 22and is engaged with the latch gear 50.

A housing 30 is placed between the base 20 and the cover plate 40, andincludes a first support shaft 34 for supporting a first elastic member110.

In one embodiment, the housing 30 includes a housing body 32, the firstsupport shaft 34, and a support lever 38.

The housing body 32 is separated from the base 20 to be placed above thebase 20 (see FIG. 1), and the latch gear 50 and the pawl 60 arerotatably disposed between the base 20 and the housing body 32.

The first support shaft 34 protrudes upward from the housing body 32,and the support lever 38 protrudes downward from the housing body 32 andis coupled to the base 20.

The first elastic member 110 has a coil spring shape and is disposedoutside the first support shaft 34. Further, the first elastic member110 is supported at one side thereof (a left side in FIG. 6) on thelever body 80 of the release lever 70, and at the other side thereof (aright side in FIG. 6) on the body of the pawl 60.

The support lever 38 protrudes downward from the housing body 32 and iscoupled to the base 20 to be disposed on a route in which an extendedprotrusion 68 of the pawl 60 is rotated. Thus, when the extendedprotrusion 68 is rotated toward the support lever 38, rotation of theextended protrusion 68 is restricted while adjoining the support lever38, and the pawl 60 is rotated clockwise about the support lever 38.

A second support shaft 36 rotatably securing the latch gear 50 to thebase 20 protrudes upward from the housing body 32 and is inserted intothe second elastic member 120.

The second elastic member 120 having a coil spring shape is disposedoutside the second support shaft 36. Further, the second elastic member120 is supported at one side thereof (a right side in FIG. 6) on aportion protruding upward from the housing body 32, and the other side(a lower side in FIG. 6) of the second elastic member 120 is insertedinto a locking groove 58 of the latch gear 50.

As the latch gear 50 is rotated, the other side of the second elasticmember 120 is rotated in an arc shape with respect to the second supportshaft 36. To guide rotation of the other side of the second elasticmember 120, the housing body 32 is formed with a guide hole having anarc shape such that the second elastic member 120 can stably move.

The latch gear 50 may have any shape so long as the latch gear 50 can berotatably disposed on the base 20 to lock the striker 10 entering themounting groove 53 through the opening 22.

In one embodiment, the latch gear 50 includes: a latch body 52 formedwith the mounting groove 53 and rotatably disposed on the base 20; afirst locking portion 55 protruding from a lateral surface of the latchbody 52 and adjoining the pawl 60 at a first locking location; and asecond locking portion 57 separated from the first locking portion 55,protruding from the lateral surface of the latch body 52, and adjoiningthe pawl 60 at a second locking location.

The latch body 52 forming the body of the latch gear 50 is rotatablydisposed on the base 20 by the second support shaft 36.

The latch body 52 is formed at one side thereof with the mounting groove53, in which the other side of the second elastic member 120 isinserted, and is formed at the other side thereof with the first lockingportion 55 and the second locking portion 57.

Thus, the striker 10 is inserted into the mounting groove 53 forming aninward groove in the latch body 52.

The first locking portion 55 and the second locking portion 57 aresuccessively formed next to the mounting groove 53. When a lockingprotrusion 66 of the pawl 60 is locked to the first locking portion 55protruding outward from the latch body 52, the latch apparatus 1 is in acompletely locked state at the second locking location.

In addition, when the locking protrusion 66 of the pawl 60 is locked tothe second locking portion 57 protruding outward from the latch body 52,the latch apparatus 1 is in a safely locked state at the first lockinglocation.

The second locking location corresponds to a state wherein the striker10 is completely locked to the latch gear 50, and the first lockinglocation corresponds to a state wherein the latch gear 50 and thestriker 10 are coupled to each other before the striker 10 is separatedfrom the latch gear 50 or the striker 10 is completely coupled to thelatch gear 50.

The pawl 60 may have various shapes so long as the pawl 60 can berotatably disposed on the base 20 and engage with the latch gear 50 toprevent rotation of the latch gear 50.

In one embodiment, the pawl 60 includes: a pawl body 62 provided withthe projection pin 64 and having a lateral surface adjoining the releaselever 70 and the support shaft 90; the locking protrusion 66 extendingfrom one side of the pawl body 62 and locked to the lateral surface ofthe latch gear 50 as the pawl body 62 rotates; and the extendedprotrusion 68 extending from the other side of the pawl body 62 andselectively adjoining the support lever 38 secured to the base 20.

The projection pin 64 protrudes upward from the pawl body 62 forming thebody of the pawl 60, and the locking protrusion 66 protruding from theone side of the pawl body 62 is engaged with the first locking portion55 or the second locking portion 57 of the latch gear 50 to preventrotation of the latch gear 50.

The extended protrusion 68 protruding from the pawl body 62 in adifferent direction than the locking protrusion 66 is rotated togetherwith the pawl body 62. When the extended protrusion 68 is prevented fromrotation while adjoining the support lever 38, the pawl body 62 isrotated by the support lever 38 acting as a lever.

The pawl 60 is rotated together with the release lever 70 receivingoperating force from a handle.

In addition, a lower side of the pawl 60 is not secured to the base 20and thus slides on the base 20.

The lateral surface of the pawl 60 is disposed to adjoin the releaselever 70 and the support shaft 90. Constraint force F1 transmitted tothe latch gear 50 while the pawl 60 prevents rotation of the latch gear50 is distributed to the release lever 70 and the support shaft 90.

Therefore, the release lever 70 is rotated by a force weaker than theconstraint force F1, and the pawl 60 is rotated by rotation of therelease lever 70, thereby allowing rotation of the latch gear 50.

The release lever 70 may have any shape so long as the release lever 70can be disposed to adjoin the pawl 60, transmit the constraint force F1to press the pawl 60, and release the latch gear 50 by rotating the pawl60.

In one embodiment, the release lever 70 includes: a rotary portion 72rotatably disposed on the base 20 and pressing the pawl 60 at differentportions thereof changed when rotated; a lever body 80 coupled to therotary portion 72 to rotate together with the rotary portion 72 andtransmitting operating force manually or automatically; and a leverprotrusion 82 protruding from the lever body 80 and pressing the guideportion 100.

The release lever 70 receives the operating force of the handle providedto the door, and includes the lever body 80 rotated by external force,and the rotary portion 72 connected to the lever body 80 and rotatingtogether with the lever body 80.

A portion of the rotary portion 72 adjoining the pawl 60 varies whilethe rotary portion rotates together with the lever body 80, and thus,the rotary portion 72 may have any shape so long as the rotary portioncan control rotation of the pawl 60.

In one embodiment, the rotary portion 72 may include: a rotary body 74into which the lever body 80 is inserted and locked and which externallyforms a first curved surface 75; and a rotary protrusion 77 protrudingfrom an outer surface of the rotary body 74, adjoining the lateralsurface of the pawl 60, and externally forming a second curved surface78.

Since a projection protruding downward from the lever body 80 isinserted into and key-coupled to the rotary body 74, the rotary body 74is rotated together with the lever body 80.

The first curved surface 75 having an arc shape is formed outside therotary body 74, and the rotary protrusion 77 protruding in a lateraldirection of the rotary body 74 protrudes in a fan shape with respect tothe center of the rotary protrusion 77.

The lever protrusion 82 protruding in the lateral direction of therotary body 74 moves the guide plate 107 of the guide portion 100, suchthat the projection pin 64 can move by movement of the guide portion100.

The second curved surface 78 having an arc shape is formed outside therotary protrusion 77, and the rotary protrusion 77 adjoins the protrudedlateral surface of the pawl body 62 while being rotated by rotation ofthe rotary portion 72 with respect to the release lever shaft 84.

The release lever shaft 84 is secured to the base 20 while penetratingthe rotary body 74 and the lever body 80, whereby the rotary body 74 andthe lever body 80 can be rotated about the release lever shaft 84.

One end of the release lever shaft 84 is secured to the base 20, and theother end thereof is coupled to the cover plate 40.

The support shaft 90 may have various shapes so long as the supportshaft can be secured to the base 20, support the lateral surface of thepawl 60, and facilitate releasing operation for the pawl 60 whilereceiving the constraint force F1 of pressing the pawl 60 together withthe rotary portion 72 of the release lever 70.

In one embodiment, the support shaft 90 includes a second support shaftmember 94 secured to the base 20, and a first support shaft member 92coupled to an upper side of the second support shaft member 94 with theguide portion 100 disposed therebetween.

The guide portion 100 may have various shapes so long as the guideportion can be rotatably provided to the support shaft 90 and pressed torotate by the release lever 70, thereby guiding movement of theprojection pin 64 provided to the pawl 60.

In one embodiment, the guide portion 100 may include: a guide body 102through which the support shaft 90 passes; a guide projection 104extending from the guide body 102 and forming an inner space 105 inwhich the projection pin 64 moves; and the guide plate 107 protrudingfrom the guide body 102 and elastically adjoining the lateral surface ofthe release lever 70.

The guide portion 100 is made of a metal plate and is rotatably providedto the support shaft 90 secured to the base 20.

The support shaft 90 passes through the guide body 102 forming the bodyof the guide portion 100, and the inner space 105 having an elongatedhole shape is formed inside the guide projection 104 protrudinglaterally from the guide body 102.

The projection pin 64 of the pawl 60 passes through the inner space 105,and may be moved within the inner space 105 having an elongated holeshape.

The inner space 105 provides a space in which the projection pin 64 isfreely movable to some extent.

Since the location of the inner space 105 is varied depending uponrotation of the guide portion 100, rotation of the pawl 60 about theprojection pin 64 placed in the inner space 105 is also varied.

Here, a leaf spring having elasticity is used as the guide plate 107protruding from the guide body 102, and thus, the guide plate 107 mayelastically adjoin the lower side of the lever body 80.

The lever protrusion 82 of the release lever 70 is interposed betweenthe guide plate 107 and the guide body 102, and the guide plate 107elastically adjoins the lever protrusion 82 and the lever body 80.

The first elastic member 110 is supported at opposite sides thereof bythe pawl 60 and the release lever 70, and forces the pawl 60 and therelease lever 70 to rotate in different directions.

That is, one side of the first elastic member 110 provides elasticitythat urges the lever body 80 of the release lever 70 to rotate in onedirection (the clockwise direction in FIG. 6). In addition, the otherside of the first elastic member 110 provides elasticity that urges theextended protrusion 68 of the pawl 60 to rotate in the other direction(the counterclockwise direction in FIG. 6).

The second elastic member 120 is supported at one side thereof by thehousing 30 and is prevented from moving, and the other side of thesecond elastic member 120 is inserted into the locking groove 58 of thelatch gear 50 and provides elasticity that urges the latch gear 50 torotate in one direction (the clockwise direction in FIG. 6).

FIG. 7 shows forces acting on the pawl 60 in a completely locked stateof the second locking location. The release lever 70 is illustrated by adotted line, and the guide portion 100 is illustrated by a dash-dottedline.

Load due to a door seal disposed along an edge of the door causes torqueon the latch gear 50.

Thus, constraint force F1 is transmitted to the surface of the pawl 60having a first radius R1 from a pin center A of the projection pin 64 toone end of the locking protrusion 66 adjoining the latch gear 50.

A distance from the pin center A of the projection pin 64 to the pawlbody 62 adjoining the support shaft 90 is set as a second radius R2, anda distance from the pin center A to the pawl body 62 adjoining therotary portion 72 is set as a third radius R3.

First reaction force F2 is created on the support shaft 90 adjoining thepawl body 62, and second reaction force F3 is created on the rotaryportion 72 adjoining the pawl body 62.

All of the constraint force F1, the first reaction force F2 and thesecond reaction force F3 pass through the pin center A of the projectionpin 64, and thus, no torque is applied to the pawl 60. In addition,since the first radius R1, the second radius R2 and the third radius R3have a center placed at the pin center A of the projection pin 64, noload is applied to the projection pin 64.

FIG. 8 shows a force diagram in which the second reaction force F3 issmaller than the constraint force F1.

The release lever 70 operated to release the latch gear 50 is rotated inthe counterclockwise (see FIG. 10b ) by operation of the door handle.

Since the rotary portion 72 provided to the release lever 70 is alsorotated, the shape of the rotary portion 72 supporting the lateralsurface of the pawl 60 is changed and thus, the pawl 60 is rotated inassociation with the rotary portion 72.

Since the second reaction force F3 is smaller than the constraint forceF1, and friction for releasing the constraint force F1 is smaller thanthat for releasing the second reaction force F3, the pawl 60 can berotated by rotating the release lever 70 with a force weaker than theconstraint force F1.

FIG. 7 shows whether the rotation center of the pawl 60 is maintained tosubstantially correspond to the pin center A of the projection pin 64. Adistance between the outer surface of the pawl 60 adjoining the supportshaft 90 and the projection pin 64 placed at one side of the inner space105 of the guide portion 100 is limited to a value a slightly greaterthan the second radius R2.

A distance between the lateral surface of the pawl body 62 adjoining therotary portion 72 and the projection pin 64 may be kept to the thirdradius R3 by the guide portion 100 pressing the projection pin 64 in adirection of adjoining the rotary portion 72.

Since the location of the guide portion 100 is adjusted by the guideplate 107 having elasticity and adjoining the release lever 70, theprojection pin 64 inserted into the inner space 105 and the pawl 60connected to the projection pin 64 are pressed in a direction ofadjoining the rotary portion 72 of the release lever 70.

The area of the pawl body 62 adjoining the first curved surface 75 orthe second curved surface 78 of the rotary portion 72 and slidingthereon is smaller than that of the locking protrusion 66 adjoining thelateral surface of the latch gear 50. Thus, force needed for movement ofthe release lever 70 is less than that of a conventional latchapparatus.

When the rotary portion 72 is rotated and moved in a direction of beingseparated from the pawl body 62, the latch gear 50 pushes the pawl 60 ina direction of transmitting the constraint force F1, and the lateralsurface of the pawl body 62 slides and moves on the surface of thesupport shaft 90 about the support shaft 90.

The extended protrusion 68 of the pawl 60 generates torque in theclockwise direction about the support lever 38 while adjoining thesupport lever 38 and thus being restricted from moving toward thesupport lever 38.

The lever protrusion 82 protruding from the release lever 70 presses theguide plate 107 of the guide portion 100, and movement of the guideplate 107 allows the guide body 102 to move in the clockwise direction.

Such movement of the guide body 102 presses the projection pin 64 upwardin the inner space 105, thereby increasing moment about the supportshaft 90.

Movement in the direction of transmitting the constraint force F1 to thepawl 60 and rotation of the pawl 60 in the counterclockwise directionabout the support shaft 90 are continued until the pawl 60 is separatedfrom the latch gear 50.

The latch gear 50 is separated from the pawl 60 and rotated clockwise toface an opening location, as shown in FIGS. 10c and 10 d.

When the latch gear 50 is rotated, the pawl 60 is kept stationary at thelocation as shown in FIG. 10 d.

Since the release lever 70 is at the operating location and the leverprotrusion 82 of the release lever 70 pushes the guide plate 107 of theguide portion 100, the projection pin 64 of the pawl 60 placed in theinner space 105 of the guide portion 100 is kept at a preset location.

Leftward movement of the pawl 60 is prevented by the projection pin 64placed at the left side in the inner space 105, and rightward movementof the pawl 60 is prevented by the support shaft 90.

After the latch gear 50 moves to a release location, the handle of thedoor is returned to a stationary location by a user. The release lever70 and the rotary portion 72 provided to the release lever 70 arerotated by elasticity of the second elastic member 120, and the pawl 60adjoins the latch body 52 of the latch gear 50, as shown in FIG. 10 e.

The pawl 60 is pressed to allow the surface of the rotary portion 72 andthe surface of the pawl body 62 to be in contact with each other, andthe projection pin 64 of the pawl 60 is moved to press the guide body102 in the counterclockwise direction about the support shaft 90.

With the elasticity of the first elastic member 110 urging the extendedprotrusion 68 of the pawl 60 upwards, the pawl 60 is rotated in thecounterclockwise about the support lever 38.

In addition, the lever protrusion 82 of the release lever 70 moves awayfrom the guide plate 107, and the locking protrusion 66 of the pawl 60presses the latch gear 50.

The release lever 70 may be rotated by drive force from a drive device,such as an electric actuator or the like, instead of the operating forcetransferred from the handle.

In addition, the guide plate 107 of the guide portion 100 may be pressedby a protrusion on the rotary portion 72 instead of the lever protrusion82 of the release lever 70.

Next, operation of the latch apparatus 1 according to the embodiment ofthe invention will be described in detail with reference to theaccompanying drawings.

Referring to FIGS. 1, 2 and 9 a, operation of locking the striker 10 tothe latch gear 50 will be described.

The striker 10 is moved from right to left into the mounting groove 53of the latch gear 50, and pushes the latch gear in the counterclockwisedirection about the second support shaft 36 coupled between the base 20and the cover plate 40.

FIG. 9b shows that the striker 10 rotates the latch gear 50 to alocation near the first locking location.

The pawl 60 pushed by the striker 10 and adjoining the rotating latchgear 50 is pushed by the latch gear 50 to rotate in the clockwisedirection.

The pawl 60 is rotated again by elasticity of the first elastic member110 in a direction of adjoining the latch gear 50.

As shown in FIG. 9c , movement of the striker 10 causes the lockingprotrusion 66 of the pawl 60 to be locked to the second locking portion57 of the latch gear 50, thereby maintaining a safely locked state atthe first locking location.

As shown in FIG. 9d , continuous movement of the striker 10 causes thelatch gear 50 to rotate such that the locking protrusion 66 of the pawl60 can climb over the first locking portion 55.

As shown in FIG. 9e , continuous movement of the striker 10 causes thelatch gear 50 to pass through the second locking location and to beadditionally rotated.

As shown in FIG. 9f , the striker 10 is locked to the latch gear 50 in astate that the locking protrusion 66 of the pawl 60 is locked to thefirst locking portion 55.

As the door is closed, the door seal is pressed to generate elasticity,which is transmitted to the pawl 60 through the latch gear 50, therebyincreasing the constraint force F1 in the pawl 60 and the latch gear 50.

At the first locking location of the safely locked state, rightwardmovement of the striker 10 is resisted by the locking protrusion 66 ofthe pawl 60 adjoining the second locking portion 57 of the latch gear50, thereby preventing rotation of the latch gear 50 in the clockwisedirection.

At the second locking location of the completely locked state, rightwardmovement of the striker 10 is resisted by the locking protrusion 66 ofthe pawl 60 adjoining the first locking portion 55 of the latch gear 50,thereby preventing rotation of the latch gear 50 in the clockwisedirection.

The striker 10 enters the mounting groove 53 of the latch gear 50 fromthe opening location of the latch gear 50 to the locking location of thelatch gear 50 and rotates the latch gear 50 in the counterclockwisedirection.

The locking protrusion 66 of the pawl 60 climbs over the outer surfaceof the latch gear 50 when the latch gear 50 is rotated.

Operation of releasing the striker 10 will be described with referenceto the accompanying drawings.

The release lever 70 shown in FIG. 10a is connected to the door handleby a link, a cable or the like, and receives external force.

Referring to FIG. 10b , when the door handle is operated, the releaselever 70 is moved in the counterclockwise direction.

The release lever 70 is rotated in the counterclockwise direction fromthe completely locked location, as shown in FIG. 10 a.

FIG. 10b shows the release lever 70 partially rotated in a releasingdirection and the pawl 60 partially moved to a releasing location. FIG.10c shows the release lever 70 completely rotated in the releasingdirection and the pawl 60 completely moved to the releasing location.FIG. 10d shows the latch gear 50 rotated to the releasing location byelasticity of the second elastic member 120, and FIG. 10e shows therelease lever 70 returned to a neutral location by elasticity of thefirst elastic member 110.

As described above the constraint force F1 transmitted to the pawl 60through the latch gear 50 is distributed to the rotary portion 72 andthe support shaft 90 adjoining the pawl 60, and thus, the latch gear 50can be easily opened by a force weaker than the constraint force F1transmitted to the pawl 60.

Next, a latch apparatus 1 according to another exemplary embodiment ofthe invention will be described with reference to the accompanyingdrawings.

For convenience of description, components having the same structuresand functions as those of the above embodiment will be indicated by thesame reference numerals, and detailed descriptions thereof will beomitted.

FIGS. 11a to 11f show a locking sequence of a latch apparatus accordingto another embodiment of the present invention, and FIGS. 12a to 12eshow an opening sequence of a latch apparatus according to anotherembodiment of the present invention.

In this embodiment, the latch apparatus 1 includes a movable connectingmember 130 connected to the release lever 70 and moving together withthe release lever 70; and a coupling 140 having an operation space 142in which the movable connecting member 130 is locked and moved, andmoved by receiving operating force from a handle element 150.

Referring to FIG. 11a , a latch gear 51 includes a tail 59 having apreset radius.

The coupling 140 having the operation space 142 is provided between therelease lever 70 and the handle, and the other side of the movableconnecting member 130 connected to the release lever 70 is movable alongthe operation space 142 of the coupling 140.

FIG. 12a shows the latch gear 51 at a second locking locationcorresponding to the completely locked state, and the handle element isat a stationary location.

In FIG. 12d , the handle element 150 is moved down from location A tolocation B and is then returned to location B. As the handle element 150is moved from the location A to the location B, the release lever 70 isrotated in the counterclockwise direction, whereby the striker 10 can bereleased from the latch gear 51.

As shown in FIG. 11a , even when the handle element 150 is returned tothe location A, one end of the movable connecting member 130 movestoward a lower side of the operation space 142 provided to the coupling140, whereby the release lever 70 can be maintained in a released state.

Although the release lever 70 is pressed in the clockwise direction byelasticity of the first elastic member 110, the release lever 70 isprevented from rotating by engaging with the pawl 60.

The latch gear 51 is moved to a release location in the clockwisedirection, and the tail 59 of the latch gear 51 adjoins the lockingprotrusion 66 of the pawl 60, thereby preventing the pawl 60 from movingin the counterclockwise direction.

In addition, the pawl 60 adjoins the rotary portion 72 and thus preventsthe rotary portion 72 from rotating in the clockwise direction. Therotary portion 72 is coupled to the lever body 80, and thus the leverbody 80 and the rotary portion 72 are rotated together, therebypreventing the release lever 70 from rotating in the clockwisedirection.

Transition from the second locking location corresponding to thecompletely locked state shown in FIG. 12a to the release location shownin FIG. 12d is achieved by operation of the handle element 150.

From the second locking location corresponding to the completely lockedstate shown in FIG. 12a , the handle element 150 of the door is moveddown and moves the latch gear 51 in the release direction, as shown inFIGS. 12b and 12 c.

Since the movable connecting member 130 is placed at an upper side ofthe operation space 142 of the coupling 140, downward movement of thehandle element 150 causes the coupling 140 to move down and the movableconnecting member 130 inside the coupling 140 is also moved down,thereby rotating the release lever 70 in the counterclockwise direction.

FIG. 12b illustrates that the handle element 150 is partially moved downin the direction of releasing the latch gear 51, and the release lever70 and the pawl 60 are partially moved to the location of releasing thelatch gear 51.

FIG. 12c illustrates that the handle element 150 is completely moved tothe location of releasing the latch gear 51, and the release lever 70and the pawl 60 are completely moved to the location of releasing thelatch gear 51 in association with the handle element 150.

FIG. 12d illustrates the latch gear 51 rotated to the release location,and FIG. 12e illustrates that the release lever 70 is not rotated andonly the handle element 150 is returned to an initial location while thelocking protrusion 66 of the pawl 60 is in contact with the tail 59 ofthe latch gear 51.

The rotary portion 72 of the release lever 70, the lever body 80, theguide portion 100 and the pawl 60 shown in FIGS. 12a to 12d are operatedin the same manner as those of the foregoing exemplary embodiment.

However, the release state of the latch gear 51 shown in FIG. 12e isdifferent from the final release state of the latch gear 50 shown inFIG. 10e according to the foregoing exemplary embodiment.

That is, in FIG. 10e , the release lever 70, the rotary portion 72 andthe pawl 60 are not prevented from moving in the release location of thelatch gear 50 and are returned to the initial location as shown in FIG.10a , since the latch gear 50 does not include the tail 59.

The rotary portion 72 of the release lever 70, the lever body 80 and thepawl 60 are reset to the location shown in FIG. 12a while the latch gear51 is locked.

FIGS. 11a to 11f show the locking sequence of the latch gear 51. In thecompletely released location as shown in FIG. 11a , the handle element150 is placed at the upper side.

As shown in FIG. 11b , when the latch gear 51 reaches the first lockinglocation corresponding to the safely locked state, the lockingprotrusion 66 of the pawl 60 is separated from the surface of the tail59 of the latch gear 51.

The pawl 60 is not prevented from rotating in the counterclockwisedirection, and also the rotary portion 72 and the lever body 80 are notprevented from rotating in the clockwise direction.

The lever body 80 and the rotary portion 72 of the release lever 70, andthe pawl 60 are rotated to the initial location by elasticity of thefirst elastic member 110.

As such, in the latch apparatus according to the present invention,constraint force transmitted to the pawl through the latch gear isdistributed to the rotary portion and the support shaft adjoining thepawl, whereby the latch gear can be easily opened even by a force weakerthan the constraint force transmitted to the pawl.

Although some embodiments have been described herein, it should beunderstood by those skilled in the art that these embodiments are givenby way of illustration only, and that various modifications, variations,and alterations can be made without departing from the spirit and scopeof the invention. In addition, the latch apparatus disposed in a doorfor vehicles is just for illustrative purpose, and may be applied toother mechanisms for opening the door. Therefore, the scope of theinvention should be limited only by the accompanying claims andequivalents thereof.

What is claimed is:
 1. A latch apparatus comprising: a base formed withan opening; a latch gear formed with a mounting groove to lock a strikerentering the mounting groove through the opening; a pawl rotatablydisposed on the base and engaging with the latch gear to preventrotation of the latch gear; a release lever disposed to adjoin the pawl,transmitting a constraint force for pressing the pawl, and rotating thepawl to release the latch gear; a support shaft secured to the base,supporting a lateral surface of the pawl and transmitting the constraintforce for pressing the pawl; and a guide portion rotatably provided tothe support shaft, which is pressed to rotate by the release lever so asto guide movement of a projection pin provided to the pawl; wherein therelease lever comprises: a rotary portion rotatably disposed on the baseand pressing the pawl at different portions thereof when rotated; alever body coupled to the rotary portion to rotate together with therotary portion so as to transmit an operating force manually orautomatically; and a lever protrusion protruding from the lever body andpressing the guide portion, wherein the rotary portion comprises: arotary body into which the lever body is inserted and locked, and whichexternally forms a first curved surface; and a rotary protrusionprotruding from an outer surface of the rotary body, adjoining thelateral surface of the pawl, and externally forming a second curvedsurface, wherein the guide portion comprises: a guide body through whichthe support shaft passes; a guide projection extending from the guidebody and forming an inner space in which the projection pin moves; and aguide plate protruding from the guide body and elastically adjoining alateral surface of the release lever.
 2. The latch apparatus accordingto claim 1, wherein the latch gear comprises: a latch body formed withthe mounting groove and rotatably disposed on the base; a first lockingportion protruding from a lateral surface of the latch body andadjoining the pawl at a first locking location; and a second lockingportion separated from the first locking portion, protruding from thelateral surface of the latch body, and adjoining the pawl at a secondlocking location.
 3. The latch apparatus according to claim 1, whereinthe inner space comprises an elongated hole.
 4. The latch apparatusaccording to claim 1, further comprising: a first elastic membersupported at opposite sides thereof by the pawl and the release lever soas to press the pawl and the release lever to rotate in differentdirections.
 5. The latch apparatus according to claim 1, furthercomprising: a movable connecting member connected to the release leverand moving together with the release lever; and a coupling forming anoperation space in which the movable connecting member is locked andmoved, and moved by operating force received from a handle element.